Summary: What will computers look like in the future and how will
they function? The answer to these questions could be
the quantum computer, the most powerful computing
device the world has ever known. But creating such a
computer is no easy feat. One of the biggest challenges
lies in the delicate temperament of the most basic compo-
nent of the quantum computer: the qubit. In a convention-
al computer, transistors store bits of information and each
bit has a value of either a 1 or 0. The power to motivate a
bit is electricity. With a quantum computer, the classical
bit gives way to a quantum bit, or qubit. Qubits are very
sensitive to their environment, and are not stored in tran-
sistors; rather, they can be stored in a quantum mechani-
cal state such as a photon polarization, electron spin, or in
even more exotic degrees of freedom.
About seven years ago, seeing the looming challenges to
Moore's Law1
, Microsoft made a bet that quantum com-
puters could be developed. A key person leading Micro-
soft to this conclusion was a then Distinguished Engineer